A method of manufacturing pipe body by which pipe body with precise quality and closely contacted seam can be made stably by pressing process, and pipe body manufactured by the method are provided. To manufacture a pipe body 1 made of metal with circular or polygonal cross section comprising a seam 5e and a wall 2 or plurality of walls 2, 3 and 4, a pipe-like intermediate product 14 is made by bending a metal plate 6 of which edges to be seam 5e have not yet contacted together. In case for prism pipe, the intermediate product comprises walls 5a, 5b to be contacted and be a wall including seam, and other walls, and both angles of both ends of one specified wall 15 of the intermediate product are larger than those of completed pipe. External forces are applied to adjoining walls 16, 16 of the one specified wall 15 so as for the one specified wall 15 to include convex portion 32 to outer side and for the seam 5e to be closely contacted together, then another external force is applied to the one specified wall 15 so as to be flat and to be the completed pipe 1. A spring back force tending the one specified wall to be back as original convex form is induced and it maintains the seam 5e in dose contacted condition. In case for cylindrical pipe, the intermediate product has an oval cross section with its seam contacted together, and an external force is applied in long axis direction of the oval so as for the oval to be circular and to be a completed pipe 1. A spring back force tends the pipe to be back as original oval form is induced and it maintains the seam 5e in close contacted condition.